Chemical Engineering - Fluid Mechanics - Discussion

Mach number also determines whether a flow is subsonic, transonic, or supersonic.

Flow is compressible when Mach number is greater than 0.3.

Yes, option Number B is correct.

Mach no. = inertia force/elastic force.

The elastic force will change with change in compressibility.

While all flows are compressible, flows are usually treated as being incompressible when the Mach number (the ratio of the speed of the flow to the speed of sound) is less than 0.3 (since the density change due to velocity is about 5% in that case).

The study of compressible flow is relevant to high-speed aircraft, jet engines, rocket motors, high-speed entry into a planetary atmosphere, gas pipelines, commercial applications such as abrasive blasting, and many other fields.

The Mach number is primarily used to determine the approximation with which a flow can be treated as an incompressible flow.

Mach number is speed of fluid/speed of fluid in sound.

Reynolds number: Inertial forces/ viscous forces,

Mach number: Inertial forces/ elastic forces,

Euler number: Pressure forces / inertial forces,

Weber number: Inertial forces/ Surface tension.